<div class="container"></div>

<style>
/* From Uiverse.io by Juanes200122  - Tags: simple, blue, pattern */
.container {
  position: absolute;
  width: 100%;
  height: 100%;
  perspective: 1000px;
  background: linear-gradient(45deg, #3498db 25%, transparent 25%),
    linear-gradient(
      -45deg,
      #3498db 25%,
      transparent 25%,
      transparent 75%,
      #3498db 75%,
      #3498db
    );
  background-size: 50px 50px;
}

</style>
    